Abstract：To study the response of anammox bacterial and other bacterial community changes in dryland deep soils to water increase, soil samples at illuvium and parent material layers were collected from the typical dryland soil at 60 m depth in Kalgoorlie, Western Australia, and incubated with freshwater or salty water (3.5%). The higH-throughput sequencing aimed at the hydrazine synthase β-subnit gene (hzsB) of anammox bacteria and 16S rRNA gene of total bacteria were performed. The results showed that no anammox bacteria was detected in original soils. After three months of incubation, anammox bacteria began to be detected, and their diversity were higher in salty water than that in freshwater. In freshwater, the illuvium and parent material soil layers had similar anammox bacterial community compositions, which were dominated by Candidatus ‘Brocadia anammoxidans’ (92.09% and 91.94%). In salty water, the illuvium soil layer was dominated by Candidatus ‘Brocadia anammoxidans’ (50.03%) and Candidatus ‘Jettenia sp.’ (40.25%), while the parent material soil layer was dominated by Candidatus ‘Jettenia sp.’ (71.20%); After four months of incubation, the anammox bacterial diversity increased in both freshwater and salty water, and they were still higher in salty water than that in freshwater. In freshwater, the illuvium soil layer was still dominated by Candidatus ‘Brocadia anammoxidans’ (87.88%), while the parent material soil layer was dominated by Candidatus ‘Jettenia sp.’ (50.90%) instead of Candidatus ‘Brocadia anammoxidans’ (39.92%). In salty water, the illuvium soil layer was dominated by both Candidatus ‘Brocadia fulgida’ (45.19%) and Candidatus ‘Brocadia anammoxidans’ (47.99%), while Candidatus ‘Brocadia fulgida’ (73.14%) rather than Candidatus ‘Jettenia sp.’ (13.65%) dominated in the parent material soil layer. The total bacterial community compositions kept relatively stable during the incubation, it was dominated by Proteobacteria (81.84%~95.45%), among which the majority part were typical marine bacterial family Halomonadaceae and Shewanellaceae. Meanwhile, the relative abundance of Firmicutes showed some increase during the incubation. There existed significantly positive relations between the relative abundance of Candidatus ‘Jettenia sp.’ and Actinobacteria (r=0.991, p=0.009), and significantly negative relations between the relative abundance of Candidatus ‘Jettenia sp.’ and Shewanellaceae (r=-0.971, p=0.029). In conclusion, this study revealed the effects of water added incubation on the occurrence of anammox and their bacterial community compositions, further expanded the understanding of anammox bacterial physiological characteristics in different habitats.